镍粉填充型磁流变弹性体压敏与温敏电阻特性研究

Study on piezoresistivity and thermosensitivity of magnetorheological elastomers filled by nickel particles

磁流变弹性体具有良好的压致电阻敏感特性和温度-电阻敏感特性,在柔性触觉传感领域表现出应用潜力。以羰基镍粉作为导电填充颗粒,硅橡胶作为基体,分别制备了镍粉随机分散和磁致链化的磁流变弹性体样品,测试了磁流变弹性体在不同温度下的压力-电阻特性和定值压力下的温度-电阻特性。分析了镍粉体积分数、外加电压、镍粉磁致链化对磁流变弹性体压阻特性的影响和不同温度下磁流变弹性体的压敏电阻规律。研究表明,体积分数为26%的磁流变弹性体在较低加载电压下,不仅其对数电阻与压力具有较好的线性关系,而且压力感知范围较宽;磁致链化可显著提高MRE压阻灵敏度;在不同恒定压力下,温度-电阻曲线具有一致的变化规律,呈现出先降后升的特性。

Magnetorheological elastomer （MRE） has potential in the field of flexible tactile sensing because of its good pressure and temperature sensitive resistance features. Using carbonyl nickel powders as the filling conductive media and silicone rubber as the matrix, MRE samples with uniform particle dispersion and magnetically structured particle chains were prepared, respectively. The piezoresistivity properties at different temperatures and the thermosensitivity behaviors were investigated respectively. The effects of particle volume fraction, voltage, and magnetic chains of nickel powders on the piezoresistivity of MRE were analyzed. Besides, the piezoresistivity of MRE under different temperatures was also analyzed. The results show that at low voltages, the MRE with particle volume fraction of 26 % has a good linear relationship between the pressure and the logarithmic resistance, as well as a wide pressure-sensing range. MRE with magnetic chain structures significantly enhances its piezoresistive sensitivity. In addition, when there exists a consistent trend, all the temperature-resistance curves under different constant pressures decline first and then rise.